JP7212155B2 - Moment frame with lateral reinforcement system and treated beams - Google Patents

Description

This application is made by U.S. Provisional Application No. 62/743,176, entitled "MOMENT FRAME INCLUDING LATERAL BRACING SYSTEM AND COPED BEAM," filed October 9, 2018, and U.S. nonprovisional application filed October 8, 2019 No. 16/595,940, entitled "MOMENT FRAME INCLUDING LATERAL BRACING SYSTEM AND COPED BEAM," which applications are hereby incorporated by reference in their entireties.

The present invention relates to hysteretic damping of structures used in lightweight framed structures, in particular high energy dispersion due to hysteretic damping with high initial stiffness, such that the energy is distributed at low displacement thresholds in lightweight framed structures. It relates to a lateral reinforcement system configured to achieve strength.

Shear stresses caused by natural phenomena such as seismic activity and strong winds can have devastating effects on the structural integrity of lightweight framed structures. Lateral forces that occur during such natural phenomena can move the upper part of the wall laterally relative to the lower part of the wall, and that movement can result in wall damage or structural failure. Depending on the situation, buildings may collapse.

In structures such as houses and small buildings, lateral reinforcement systems have been developed to counter the potentially destructive effects of shear stress on the structural integrity of lightweight framed structures. While various designs are known, one type of transverse reinforcement system comprises longitudinal studs spaced from one another and transverse beams attached to and extending between the studs. The beams are attached to studs for the purpose of increasing the structural performance of the joint under lateral loads.

Many conventional lateral reinforcement systems initially perform well under lateral loads, but yield or fail under repeated lateral loads, which often occur during large seismic activity and high winds. If a lateral reinforcement system yields or fails, the entire system must be replaced.

Another consideration relates to the clearance between components when the beam rotates relative to the column under lateral loads.

FIG. 4 is a front view of a beam connected to a column by a lateral stiffening system according to an embodiment of the invention;

FIG. 4 is a perspective view of a beam connected to a column by a lateral stiffening system according to an embodiment of the invention;

FIG. 4 is a front view of a beam connected to a column by a lateral reinforcement system and shear tabs according to an embodiment of the invention;

FIG. 12 is a front view of a beam adjacent to a column showing treatment of the beam according to embodiments of the present technology;

FIG. 15 is a partial enlarged front view of a beam, column and shear tab in accordance with embodiments of the present technology;

FIG. 23 is an exploded perspective view of a buckling restraint assembly and a treated beam in accordance with embodiments of the present technology;

2 is an exploded perspective view of a buckling restraint assembly in accordance with embodiments of the present technology; FIG.

The invention will now be described with reference to the drawings, which in embodiments have high initial stiffness and effectively dissipate the energy generated in the lateral reinforcement system under lateral loads. It relates to a lateral reinforcement system with a yield link capable of It should be understood that this invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the invention to those skilled in the art. Indeed, the invention is intended to cover alternatives, modifications and equivalents of these embodiments that fall within the scope and concept of the invention as defined by the appended claims. Moreover, in the following detailed description of the invention, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that the present invention may be practiced without such specific details.

1-3 and 7, for example, a frame 100 consisting of a portion of transverse beams 102 attached to longitudinal posts 104 is shown. Each beam 102 and column 104 comprises a pair of opposing flanges connected by a central diaphragm or web. Beams 102 may include, for example, flanges 110 and webs 112 . Although referred to as longitudinal columns and transverse beams, it should be understood that the columns and beams may be attached to each other at angles other than 90° in alternate embodiments. Beams 102 and columns 104 may be I-beams, W-beams, or other structural steel elements.

Beam 102 is attached to column 104 using lateral reinforcement system 300 . The lateral stiffening system consists of a pair of anti-buckling stiffeners 302 , one on each of the upper and lower flanges 110 of the beam 102 . Each buckling restraining stiffener 302 is bolted, welded, or glued at its first end to the flange 110 of the beam 102 and bolted, welded, or glued at its second end to the flange 110 of the column 104 . It may comprise a glued flat, "dog-bone" shaped yielding member 304 (FIG. 7) (where the yielding member is narrower in the center 312 than at the ends). A buckling restraint block 316 covers the central portion of each yielding member 304 . Blocks 316 are bolted, welded, or glued to respective flanges 110 of beam 102 .

A shear tab 222 may also be provided between the beam 102 and the column 104 . The shear tab 222 may be attached to the flange of the column 104 by bolting, welding, gluing, etc., and to the central diaphragm 112 of the beam 102, such as by bolting. As shown, shear tab 222 may include bolt holes 228 including a central bolt hole 228a and a pair of end bolt holes 228b. The central bolt hole 228a may be circular, while the end bolt holes 228b may be oval with the length dimension arranged parallel to the flange 110 of the beam 102 when assembled. As explained below, when a lateral load of sufficient magnitude is applied, the beam 102 can rotate about an axis through the central bolt hole 228a. The oblong end bolt holes 228b allow the bolts attached to the central diaphragm of the beam 102 to move within the end bolt holes as the beam 102 rotates relative to the post 104 .

In operation, the pair of anti-buckling stiffeners 302 work together to counteract rotation of the beam with respect to the column (ie rotation of the shear tabs 222 about the central hole 228a) under lateral loads. Attempting to rotate in a first direction pulls the first device 302 and compresses the second device. Attempting to rotate in the opposite direction compresses the first device and pulls the second device.

The yielding member 304 of each device 302 exhibits high initial stiffness and tensile resistance to relative motion of the column 104 and beam 102 under lateral loads, but under lateral loads exceeding predictable and controllable levels. has a stable yield and energy dispersion. In particular, the flexural strength of the columns and beams may be designed to exceed the moment capacity of the yielding member 304, especially the thinner central portion of the yielding member 304. Yield member 304 thereby yields under lateral loads prior to yielding or failure of the column or beam, and any damage is limited to the yielding link, which can be easily removed and replaced. A buckling restraint block 316 prevents buckling of the yielding member under compressive loads. Shear tabs 222 are provided to counter longitudinal shear forces (ie, longitudinally of column 104) that occur under longitudinal loading or upon lateral loading of the reinforcement system. Shear tabs 222 are also provided to counter axial forces (ie, longitudinally of beam 102) under lateral loading of the reinforcement system.

As noted in the Background of the Invention section, one advantage of this technique is to avoid interference and binding between components when beam 102 rotates relative to column 104 under lateral loading. For example, in one embodiment, beam 102 is treated to provide a sloping portion 114 (eg, numbered in FIG. 4) at the end adjacent column 104 . Each yielding member 304 may comprise a longitudinal plate 308a attached to the post 104, as described below. In embodiments, the angled portion 114 removes portions of the upper and lower flanges 110 of the beam 102 that would otherwise interfere with the column mounting plate 308 of the yield member 304 when the beam 102 is rotated. or may be detained.

Angled portion 114 forms an extended web portion 112a to which shear tab 222 is bolted. Each angled portion 114 may form an angle θ with flange 110 that may vary from 40° to 80°, such as 60°, although angle θ may be smaller or larger in alternative embodiments. . In embodiments, the flanges may be treated such that each flange 110 may terminate (and the angled portion 114 begins) at an end point 110a, eg, 3 inches from the tip of the extended web portion 112a. This position is aligned along a transverse (longitudinal) axis t, orthogonal to the plane of flange 110, passing through the center point of central bolt hole 228a. However, it is also possible that the end point 110a of each flange 110 may terminate at a point spaced forwardly or rearwardly from the transverse axis t. For example, each flange may terminate at a point 1/8 inch or 1/16 inch forward or backward from the transverse axis t. The end point 110a of the flange 110 may terminate at a different distance from the transverse axis t in other embodiments.

Treating the beam 102 in this manner provides advantages because the flange 110 may abut, interfere, or bind to the post mounting plate 308 if the beam 102 is not treated as described above. Since plate 308 can offer a significant degree of resistance to this action, forces are generated within the beam that create undesirable additional shear forces on the bolts of shear tabs 222 . Additionally, abutting the post mounting plate 308 creates undesirable forces in the post mounting plate 308 and the yield member 304 as well as the bolts, welds, or adhesives that secure the post mounting plate 308 to the post 104 .

However, by treating beam 102 as described herein, these problems are avoided. FIG. 5 shows the radius r followed by the end point 110a of the flange 110 as the beam rotates about the central bolt hole 228a. As shown, when treated as described herein, the beam does not come into contact with the post mounting plate 308 when rotated in either direction.

6 and 7 show more detail of the lateral stiffening system 300 and the yielding member 304. FIG. Each yielding member 304 comprises a column mounting plate 308, a beam mounting plate 310, and a yielding plate 312 connected between the column mounting plate and the beam mounting plate. The post mounting plate 308 may have a longitudinal portion 308a and a transverse portion 308b that may be welded together at right angles. Longitudinal portion 308a and transverse portion 308b may be joined together by other means, or may be cast as a single piece in another embodiment.

Lateral portion 308 b may be formed as a flat, unitary structure with beam mounting plate 310 and yield plate 312 . Transverse portion 308b and plates 308, 310 and 312 may be formed from a single piece of 1/4 inch steel, for example. In other embodiments, lateral portion 308b and plates 308, 310 and 312, for example, can be formed with other thicknesses.

Post mounting plate 308 and beam mounting plate 310 may each have a width (across the width of the flange of beam 102) approximately equal to the width of beam 102, eg, 7.00 inches. Yield plate 312 may have a width (across the width of the flange of beam 102) that is less than the width of plates 308,310. The width of plate 312 may be 1-6 inches in some embodiments, 1-3 inches in other embodiments, and 2-3 inches in other embodiments. The width of the yield plate 312 may be of other dimensions as long as the yield plate has a smaller width than the column and beam mounting plates 308,310.

Buckling restrained assembly 302 further comprises a buckling restraining member 316 and a pair of spacer blocks 318 (one of which has been omitted from FIG. 7 for clarity). Buckling restraint member 316 may be a flat plate having a length (longitudinal of beam 102 ) approximately equal to the length of yield plate 312 . Buckling restraint member 316 may be longer or shorter than yield plate 312 in alternative embodiments. Buckling restraint member 316 may be 1/4 inch steel, but may be thicker or thinner in alternative embodiments.

Spacer blocks 318 are positioned on either side of yield plate 312 between lateral portion 308b of column mounting plate 308 and beam mounting plate 310 when buckling restrained assembly 302 is assembled together as described below. sized to fit into the Spacer block 318 may have the same thickness as yield member 304 .

A yielding member 304 comprising a column mounting plate 308, a beam mounting plate 310, and a yielding plate 312 can be attached to the column 104 either on-site or off-site. In one embodiment, the longitudinal section 308a includes holes 320 (FIG. 7) above and below the transverse section 308b to receive bolts 322 (FIG. 6), thereby allowing the yielding member 304 to be bolted to the column 104. can. In another embodiment, it is contemplated that yielding member 304 may alternatively be attached to column 104 by welding or gluing.

The beam mounting plate 310 can then be bolted to the beam 102 via a plurality of bolts 326 in the field. The figure shows six bolts 326, but other embodiments may have more or less. At this point, yielding member 304 is attached to both beam 102 and column 104 . The beams and columns may also be attached to each other by shear tabs 222 as described above. The shear tabs 222 can be attached to the columns 104 by welding, gluing, bolting, etc. to the flanges of the columns 104 and to the webs of the beams 102 by bolts or the like.

In embodiments, the buckling restraint assembly 302 and shear tab 222 may attach the beam 102 to the column 104 on site using only bolts, thereby simplifying construction by eliminating welding. However, in another embodiment, beam mounting plate 310 and/or shear tab 222 may be attached to beam 102 by welding or gluing. In another embodiment, the yielding member 304 can be attached first to the beam 102 and then to the column 104, either in advance or on site.

Although the invention has been described in detail herein, it is to be understood that the invention is not limited to the embodiments disclosed herein. Various modifications, substitutions, and alterations can be made to those embodiments by those skilled in the art without departing from the spirit or scope of the invention as described and defined by the appended claims.
The following items are claimed elements as originally filed:
[Item 1]
a structure,
a vertical column;
a transverse beam with upper and lower flanges;
a shear tab longitudinally oriented and attached between said column and said beam and between said upper and lower flanges of said beam;
a lateral stiffening system mounted between said column and said beam;
said lateral reinforcement system comprising first and second buckling restraint assemblies on said upper and lower flanges of said beam, respectively;
each buckling restraint assembly comprising:
a post mounting plate comprising a transverse portion and a longitudinal portion, the longitudinal portion being attached to the post;
a beam attachment plate comprising a lateral portion attached to the beam;
A yielding plate connected between the column mounting plate and the beam mounting plate, the yielding plate having a narrower width than the column mounting plate and the beam mounting plate, the narrower width of the yielding plate being defining a first notch and a second notch on opposite sides of the yield plate between the column mounting plate and the beam mounting plate, wherein the yield plate applies a lateral load to the beam and/or the column; a yield plate that yields in tension and compression to distribute stress in the structure;
the beam is treated to prevent the beam flange from binding with the post mounting plate when the beam is rotated relative to the post;
Structure.
[Item 2]
The beam includes a web between the upper flange and the lower flange, the corners of the web providing anchorage of the web with the post mounting plate when the beam is rotated with respect to the post. A structure according to item 1, which has been treated to prevent.
[Item 3]
The beam comprises a web between the upper flange and the lower flange, the web comprising an extended web portion adjacent the column, the extended web extending from the corner between the column and the beam flange. A structure according to item 1, comprising a sloping portion formed by treating said beam at a section.
[Item 4]
4. The structure of claim 3, wherein the beam flange terminates at a first end of the angled portion where the angled portion meets the beam flange.
[Item 5]
5. The structure of item 4, wherein said angled portion has a second end that terminates at said shear tab.
[Item 6]
The angled portion comprises a first angled portion, the corner portion comprises a first corner portion at the upper flange, and the extension portion comprises a second corner portion between the post and the lower beam flange. 4. The structure of item 3, further comprising a second sloped portion formed by treating said beam at a section.
[Item 7]
7. The structure of item 6, wherein the lower beam flange terminates at a first end of the second angled portion where the second angled portion meets the lower beam flange.
[Item 8]
8. The structure of item 7, wherein the second angled portion has a second end that terminates at the shear tab.
[Item 9]
The structure of Claim 1, wherein said shear tab comprises a bolt hole and said treated beam comprises a flange terminating on a longitudinal axis through the center of said bolt hole.
[Item 10]
The structure of item 1, wherein the beam treatment forms an angle of 40° to 80° with the beam flange.
[Item 11]
The structure of item 1, wherein the beam treatment forms a 60° angle with the beam flange.
[Item 12]
a structure,
a vertical column;
a transverse beam with upper and lower flanges;
a shear tab longitudinally oriented and attached between said column and said beam and between said upper and lower flanges of said beam;
a lateral stiffening system mounted between said column and said beam;
wherein the lateral reinforcement system comprises first and second buckling restraint assemblies on the upper and lower flanges of the beam, respectively;
each buckling restraint assembly comprising:
a post mounting plate comprising a transverse portion and a longitudinal portion, the longitudinal portion being attached to the post;
a beam attachment plate comprising a lateral portion attached to the beam;
A yield plate connected between the column mounting plate and the beam mounting plate that yields in tension and compression when lateral loads are applied to the beam and/or the column to distribute stress in the structure. the yield plate to
The beam comprises a web between the upper and lower flanges and an extended web portion comprising a portion of the web adjacent to the column, the extended web portion extending from the top and bottom of the web. a first angled portion and a second angled portion, wherein the first angled portion and the second angled portion align the beam flange with the pillar mounting plate when the beam is rotated relative to the pillar; configured to prevent binding,
Structure.
[Item 13]
13. The structure of item 12, wherein said upper beam flange terminates at a first end of said first angled portion.
[Item 14]
14. The structure of item 13, wherein said lower beam flange terminates at a first end of said second angled portion.
[Item 15]
15. The structure of item 14, wherein the first angled portion and the second angled portion have second ends that terminate at the shear tab.
[Item 16]
13. The structure of item 12, wherein the shear tab comprises a bolt hole and the upper and lower flanges terminate on a longitudinal axis through the center of the bolt hole.
[Item 17]
13. The structure of item 12, wherein said first angled portion forms an angle with said upper beam flange of between 40° and 80°.
[Item 18]
13. The structure of item 12, wherein said first angled portion forms a 60[deg.] angle with said upper beam flange.
[Item 19]
A method of forming a structure, comprising:
(a) attaching a beam to a column using a lateral reinforcement system, said beam having a top flange and a bottom flange and a first end adjacent said top flange and a first end adjacent said bottom flange; a web having two ends, said transverse reinforcement system comprising a post mounting plate comprising a transverse portion and a longitudinal portion, said longitudinal portion being attached to said post;
(b) treating a first portion of said web away from said post at said first end to provide space for said longitudinal portion of said post mounting plate;
method including.
[Item 20]
Additionally, a second lateral reinforcement system comprises a second post mounting plate comprising a second lateral portion and a second longitudinal portion, said second longitudinal portion being attached to said post. and a method, wherein the second portion of the web is treated away from the post at the second end to provide space for the second longitudinal portion of the second post mounting plate. 20. The method of item 19, further comprising the step of:

Claims (5)

a structure,
a vertical column;
a transverse beam comprising an upper flange , a lower flange and a web between said upper flange and said lower flange ;
a longitudinally oriented shear tab mounted between said column and said beam and between said upper and said lower flanges of said beam, said shear tab extending through a plurality of bolt holes; said shear tab comprising a single longitudinal row of said plurality of bolt holes, said single longitudinal row of said plurality of bolt holes comprising a central circular bolt hole;
a lateral stiffening system mounted between said column and said beam;
The lateral stiffening system includes first and second buckling restraint assemblies on the upper and lower flanges of the beam, respectively, and a first treatment portion and a second treatment on the web. with parts
each buckling restraint assembly comprising:
a post mounting plate comprising a transverse portion and a longitudinal portion, the longitudinal portion being attached to the post;
a beam attachment plate comprising a lateral portion attached to the beam;
A yielding plate connected between the column mounting plate and the beam mounting plate, the yielding plate having a narrower width than the column mounting plate and the beam mounting plate, the narrower width of the yielding plate being defining a first notch and a second notch on opposite sides of the yield plate between the column mounting plate and the beam mounting plate, wherein the yield plate applies a lateral load to the beam and/or the column; a yield plate that yields in tension and compression to distribute stress in the structure;
The first treatment portion and the second treatment portion are configured to prevent the upper flange and the lower flange from binding with the post mounting plate when the beam is rotated with respect to the post. wherein said upper flange terminates at a first end of said first treatment portion and said first treatment portion has a second end which terminates at said shear tab, said upper flange terminating said shear tab; terminating on a longitudinal axis through the center of the central circular bolt hole,
Structure. 2. The structure of claim 1 , wherein said lower flange terminates at a first end of said second treated portion where said second treated portion meets said lower flange . 3. The structure of claim 2 , wherein said second treated portion has a second end terminating at said shear tab. A structure according to claim 1, wherein one or more treated portions form an angle of 40° to 80° with said upper flange and/or said lower flange . 2. The structure of claim 1, wherein one or more treated portions form an angle of 60[deg.] with said upper flange and/or said lower flange .

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